Some data processing systems (DPSs) include many different integrated circuits or “chips,” with each chip serving a different purpose. For instance, a DPS may include one chip for a central processing unit (CPU), another chip for random access memory (RAM), another chip for read-only memory (ROM), another chip for a graphics processing unit (GPU), and many other chips for many other purposes. The control logic and other circuitry within a chip for any particular purpose may be referred to as a “subsystem,” a “unit,” etc. For instance, a CPU may include a control unit, an arithmetic logic unit (ALU), and many other units or subsystems.
One current trend is to expand the number of different functions that can be performed by a single chip. When a single chip includes all of the different systems or subsystems needed for a particular DPS, that chip may be referred to as a “system on a chip” or an “SOC” (or “SoC”). For instance, as recognized by the Wikipedia entry for “System on a chip,” an SOC may contain “digital, analog, mixed-signal, and often radio-frequency functions—all on a single substrate.” The different units or subsystems in an SOC may be referred to as “blocks.” In particular, as explained by the Wikipedia entry for “Semiconductor intellectual property core,” a semiconductor intellectual property (IP) block is “a reusable unit of logic, cell, or integrated circuit . . . layout design that is the intellectual property of one party.” For purposes of this disclosure, a semiconductor IP block may be referred to simply as an “IP block” or a “block.”
However, some SOCs are used in DPSs that also contain additional chips. Accordingly, such an SOC need do not contain all of the different systems or subsystems that are needed by such a DPS. If a chip contains multiple IP blocks (e.g., a microcontroller or a microprocessor, along with an advanced peripheral system such as a GPU), the chip may still be referred to as an SOC, even if the SOC is used in a DPS along with one or more additional chips.